I have a decent background in 3D graphics and programming, but I'm new to game development. I'm currently exploring different possibilities and I really want to make an RPG game. I was thinking about classic 2D isometric view, but I really love how Diablo 2 looks and feels to play.

My question is - how can I achieve Diablo 2's parallax effect? Everything looks hand drawn with baked lights and shadows and looks awesome, but when you move around you notice some perspective.

For example, let's say that I drew a big hall with columns in Photoshop with an orthographic perspective (classic pixel art style, just parallel lines). How would I give parallax effect to this scene when the character moves around? If I use camera-facing sprites for everything it would probably look OK in the distance, but it would be really fake when a character comes close to a column (cylinder) for example.

Any suggestions? How did Blizzard make the parallax effect in Diablo 2?

See this screenshot: http://guidesmedia.ign.com/guides/10629/images/act2tombs.jpg